1. Field of the Invention
The present invention relates to an image printing method and an image printing apparatus, and more specifically, to an image printing method and an image printing apparatus for printing an image and information shown by an electronic watermark added to the image by causing the information to be visually perceptible.
The present invention also relates to a recording medium storing software for executing the image printing method described above.
2. Description of the Related Art
Methods of printing images based on image data have been known. Recently, printing of a photograph image by using image data representing the image obtained by a so-called digital camera has been widely carried out according to these methods.
Meanwhile, as has been described in Japanese Unexamined Patent Publication No. 9(1997)-191394, a method of embedding deep layer information, what is generally called an xe2x80x9celectronic watermarkxe2x80x9d, in various kinds of data such as image data or audio data has been proposed. The deep layer information is embedded in a manner such that the information is not perceived by normal human visual sense when the data including the information are provided for an original use. In other words, when the deep layer information is embedded in image data for example, the information is embedded in a signal component corresponding to an extremely high space frequency so that the content of the deep layer information is not visible upon reproduction of the image data.
The deep layer information of this kind has an advantage of being impossible to unintentionally delete over header information or the like conventionally added to image data.
The content of the electronic watermark to be embedded in image data cannot be seen in the reproduced image, as has been described above. Therefore, electronic watermarks can be used as encryption code. Consequently, it becomes possible for an electronic watermark regarding a copyright holder to be embedded in image data representing a photograph image, in order to prepare for copyright violation.
Therefore, when image data having an electronic watermark regarding a copyright holder are dealt with by a photographic printing system in a laboratory or the like, information regarding the copyright holder or prohibition of printing can be provided to a customer (printing requester).
However, as has been described above, since an electronic watermark is invisible in a printed image, in order to use the electronic watermark in such a manner in a photographic printing system, a troublesome task of reading the watermark from the image data by using a special electronic watermark confirming apparatus and notifying the confirmation result to the printing requester by using any means other than printing paper is necessary.
Based on consideration of the above problems, the present invention has been created. An object of the present invention is to provide an image printing method enabling easy notification of information shown by an electronic watermark to a printing requester without a troublesome task and without using means other than prints.
Another object of the present invention is to provide an image printing apparatus for carrying out such a printing method.
An image printing method of the present invention is an image printing method for obtaining an image print from image data having an electronic watermark (deep layer information which is visually imperceptible upon image reproduction, as has been described above), and the method comprises the steps of:
reading the deep layer information from the image data;
developing the deep layer information having been read into data which are visually perceptible upon image reproduction, such as into bit map data; and
printing the content of the developed data on the front and/or back of the image print.
In the case where the content of the bit map data or the like is printed on the front of an image print, the content may be printed in superposition on the image or in a blank space of the print.
As has been described above, in order to print the content of the bit map data or the like over the image, a composite image of the bit map data or the like and the image may be generated or the bit map data may be written over the image data.
The deep layer information may be generated as information instructing additional printing so that print information which can be seen upon image reproduction can be generated as the developed data, based on the deep layer information having been read.
The deep layer information read from the image data may be developed not only into bit map data, but also into character code data, and information shown by the character code data may be printed on the front and/or back of the image print by a character printer.
It is preferable for the image printing method of the present invention to enable selection as to whether or not the content of the developed data is printed, or as to where to print the content of the developed data.
It is also preferable for the image data to accompany information indicating where to print the content of the developed data so that the position can be determined based on the information.
Meanwhile, it is also preferable for the image data to accompany information indicating a permitted print quantity, or to have deep layer information, a portion of which indicates the permitted print quantity. In this manner, when the number of prints exceeds the permitted quantity, a predetermined message is preferably recorded on the prints. In this case, it is preferable for the message to be printed on the front of the prints.
The present invention provides recording medium storing software to execute the image printing method, in addition to the printing method.
Meanwhile, an image printing apparatus of the present invention is an image printing apparatus for obtaining an image print from image data including an electronic watermark (deep layer information which is visually imperceptible upon image reproduction, as has been described above), and the apparatus comprises:
deep layer information reading means for reading the deep layer information from the image data;
developing means for developing the deep layer information having been read into data which are visually perceptible upon image reproduction; and
printing means for printing the content of the developed data on the front and/or back of the image print.
It is preferable for the image printing apparatus of the present invention in the above configuration to comprise electronic watermark information reading/print information generating means for
reading information indicating additional printing from the deep layer information read by the deep layer information reading means; and for
generating print information which is visually perceptible upon image reproduction based on the information indicating the additional printing; and for
inputting the print information to the printing means as the developed data.
It is preferable for the image printing apparatus of the present invention to comprise means for selecting whether or not the content of the developed data is printed.
It is also preferable for the image printing apparatus of the present invention to comprise attached information reading means for
reading information of a position at which the content of the developed data is printed, from the image data having the information; and for
specifying the position at which the content is printed by the printing means, based on the information having been read.
It is also preferable for the image printing apparatus of the present invention to comprise means for
reading information indicating a permitted print quantity attached to the image data; and
recording a predetermined message on prints (preferably on the front side of the prints) in the case where the number of prints exceeds the permitted quantity.
Alternatively, the image printing apparatus may comprise means for
reading information which indicates the number of permitted prints and is formed as a portion of the deep layer information; and
recording a predetermined message on prints (also on the front side of the prints, preferably) in the case where the number of prints exceeds the permitted quantity.
According to the image printing method of the present invention, deep layer information read from the image data is developed into data which are visually perceptible when provided for image reproduction, and the content of the developed data is printed on the front and/or back of an image print. Therefore, the image print itself indicates the content shown by the deep layer information in a visually perceptible manner. Consequently, according to this method, the content of the deep layer information can be notified easily to a printing requester without a troublesome task and without means other than printing paper.
In the case where printing of an image is prohibited, it is preferable for the content of the deep layer information to be printed prominently in superposition to the printed image, as has been described above. In other words, a print having a copyright holder""s name or a prominent message indicating printing prohibition superposed on the image has little or no use, and the intention of prohibiting unauthorized use can be emphasized by threatening an operation that will ruin the value of the image.
Meanwhile, the method of printing the content of the deep layer information at a corner or in a blank space of the front of a print and the back as well is appropriate for the case where printing of the image itself is permitted while information regarding the image needs to be conveyed.